The present invention relates to the dispensing of products from a container using an attached pump, and more particularly to an apparatus and method for allowing a dispensing device to be advantageously used for highly viscous products.
Container-mounted pumps are often used for the dispensing of liquid home-care or personal products from a container or bottle. Generally, the pump is supplied with a syphon or "dip" tube which has been attached to the pump during assembly of the pump, and which is of a relatively narrow diameter. In this arrangement, the container or bottle is first filled with the product to be dispensed, and then the pump/dip tube combination is inserted into the filled container and attached to the bottleneck. This filling and assembly procedure leaves a column of air within the dip tube and in the pump. The column of air occurs because the dip tube is inserted into the liquid from above, and the air has no means for escaping from the dip tube during insertion, the pump inlet and/or outlet valves being normally sealed.
The column of air in the dip tube must be removed from the dip tube and pump before the product can be dispensed. The pump therefore must be "primed" by a user before any product will come out of the pump nozzle. Priming is the procedure whereby the actuator is pushed in one or more times to clear trapped air from the pump and dip tube and to draw product up the dip tube, into the pump, and out the nozzle.
The process of priming is relatively simple when the product to be dispensed is of low viscosity, as with most personal and home-care products. However, certain cosmetic products, such as makeup, are highly viscous. The high viscosity of these products makes the priming of a pump filled in the above-described conventional manner extremely difficult and time-consuming. This is because of the high viscosity of the product makes it necessary for a substantial force to pull the product up the entire length of the dip tube. Even when a dip tube of relatively large diameter is used, it may take more than 35 actuations of the actuator to prime the pump. For a consumer, this result is very undesirable. To prevent this result additional steps can be taken during the packaging operation. One method for preventing additional priming is to place a vacuum onto the pump after it has been attached to the container, thereby drawing the product up the dip tube. This procedure requires the additional assembly and disassembly steps of removing and replacing the actuator, as well as the need for opening the normally closed inlet and/or outlet valves. These additional steps can be expensive and time consuming, and can add to the cost of packaging the product.
The present invention is directed to a method and apparatus for solving the above problems. The present method and apparatus are particularly useful in that they do not require disassembly and reassembly of the pump structure during the filling process, unlike the procedure mentioned above using vacuum priming. The present invention therefore is much more economical and efficient than this method, and still provides the same advantages in terms of priming.